There is one Max contribution to ALL 401K options over all platforms ...
Solo 401(k) contribution limits
The total solo 401(k) contribution limit is up to $57,000 in 2020. There is a catch-up contribution of an extra $6,500 for those 50 or older.
To understand solo 401(k) contribution rules, you want to think of yourself as two people: an employer (of yourself) and an employee (yes, also of yourself). Within that overall $57,000 contribution limit, your contributions are subject to additional limits in each role:
As the employee, you can contribute up to $19,500 in 2020, or 100% of compensation, whichever is less. Those 50 or older get to contribute an additional $6,500 here.
As the employer, you can make an additional profit-sharing contribution of up to 25% of your compensation or net self-employment income, which is your net profit less half your self-employment tax and the plan contributions you made for yourself. The limit on compensation that can be used to factor your contribution is $285,000 in 2020.
Keep in mind that if you’re side-gigging, employee 401(k) limits apply by person, rather than by plan. That means if you’re also participating in a 401(k) at your day job, the limit applies to contributions across all plans, not each individual plan.
At your income level making a ROTH IRA contribution will not be allowed and any traditional IRA contribution will not be deductible ... it would add to the basis. When or if you ever convert the trad IRA to a ROTH the basis portion will not be taxed a second time ... you MUST keep a copy of the form 8606 with your IRA information so you or your heirs know of the basis in the account.
